Venomous
Animal Spotlights (8)[note:
clicking below will you send you to the spotlight within the "animals"
section. You will need to hit the back button to return here to go to
the next species on this list]

Tucson
has its fair share of venomous animals. However, only a few are considered
potentially life-threatening to most people (see list to left). Nonetheless,
it pays to be cautious. Never place your hands or feet anywhere you cannot
see (e.g., into burrows or shrubs, under rocks or wood, etc.). If bitten,
immediately call the Arizona
Poison and Drug Information Center at 1-800-222-1222 and seek medical attention if you are unable to call.
I have included general information about venomous animals below.

GENERAL
INFORMATION ON VENOMOUS ANIMALS

Animals
that produce toxins are generally called poisonous.
Victims can be poisoned in two ways -- by ingesting the toxins (e.g., by biting
a frog that has produced toxins on its skin) or by envenomation (e.g., by being
stung by a wasp or bitten by a rattlesnake). Thus, you are bitten or stung by
venomous animals, but you have to do the "biting"
to be poisoned by a poisonous animal. Mechanisms used to envenomate include
hair (e.g., urticating hairs of caterpillars and tarantulas), modified
egg-laying devices (e.g., stingers in wasps), and of course teeth (with
venom groove on outside or hollow inside).

Animals
use toxins offensively, defensively, or both. Offensively,
animals use toxins to subdue prey, and in some cases, to begin the digestive
process. Defensively, animals use toxins to avoid
predation and other threats. However, venom is costly to produce and valuable
for subduing prey, so using venom defensively is a last resort. Many venomous
animals are either cryptically colored (to avoid
being spotted in the first place) or are aposematically
colored (as a warning) (see When to Blend and When
to Show Off).

The effects
toxins have on the victim (mild to fatal) depend on the type of toxin, the amount
of toxin delivered, how/where the toxin was delivered, and on the individual
characteristics of the victim (species, age, health, individual sensitivity,
etc.). Some toxins (hemolytic toxins) break down
blood tissue, other toxins (neurotoxins) affect
the nervous system, and other toxins have other effects (e.g., severe pain,
tissue damage, etc.). An animal may produce a mixture of toxins, resulting in
a combination of effects (e.g., rattlesnakes often have both hemolytic and neurotoxic
elements in their venom).

Despite
the prevalence of venomous animals in and around Tucson, fatalities are extremely
rare. For example, despite having more species of rattlesnakes (11) than any
other state in the U.S., research conducted by the Arizona Game and Fish Department
and the Arizona Poison Center System found that you are more likely to be killed
by your spouse than by a rattlesnake in Arizona (4 fatalities of 1,912 bites
reported between 1989 and 1998) (Randy Babb, personal communication). If you
are bitten, call the Arizona
Poison and Drug Information Center at 1-800-222-1222.

Why
only Female Wasps, Bees, and Ants Sting

The
stingers of wasps, bees, and ants are modified ovipositors -- egg-laying
organs that have been modified to deliver venom instead of eggs. Males
don't lay eggs so didn't have an ovipositor to be modified into a stinger.

When
to Blend and When to Show Off

Species
that blend into their environment (e.g., this Western
Diamondback Rattlesnake) are said to have cryptic
coloration. Species that are conspicuously-colored (e.g., this
Sonoran Mountain Kingsnake) are said to have aposematic
coloration. If you are a delicious morsel, then you want cryptic
coloration. If you are poisonous, there are two strategies -- use cryptic
coloration so as not to be found in the first place, or use aposematic
coloration to warn the potential predator that you are dangerous, thus
saving the potential predator from poisoning and you from a bite or from
wasting any precious venom.

But
alas! This Sonoran Mountain Kingsnake (Lampropeltis pyromelana)
is NOT venomous, it is just mimicking the coloration of the Coral
Snake that is venomous. This is called Batesian
Mimicry, and the Sonoran Mountain Kingsnake is referred to as the
Batesian mimic and the coral snake is referred to as the model.

Then
again some species --like this Western Hognose Snake (Heterodon nasicus)
-- have both cryptic and aposematic coloration. Normally, the snake is
cryptically-colored and difficult to spot, but when the snake is threatened,
it will coil up and show its underside that is aposematically-colored
orange and black (it is also feigning dead). Note: this snake has only
mildly toxic venom and is not prone to bite humans.